CN113681011A

CN113681011A - Titanium-based functional material with pore diameter gradient structure, preparation method and application

Info

Publication number: CN113681011A
Application number: CN202110856204.5A
Authority: CN
Inventors: 王快社; 张婷; 王文; 乔柯; 刘强; 关肖虎; 杨娟; 何攀
Original assignee: Xian University of Architecture and Technology
Current assignee: Xian University of Architecture and Technology
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2021-11-23
Anticipated expiration: 2041-07-28
Also published as: CN113681011B

Abstract

The invention discloses a titanium-based functional material with a pore diameter gradient structure, a preparation method and application thereof. The invention utilizes the stirring friction processing technology, can promote the refinement of alloy grains, reduce the porosity of the material and improve the comprehensive performance of the material. The material is of a rough porous structure, the pore diameter of the surface layer is not consistent with that of the substrate, the growth requirements of different cells can be met, the growth of bone tissues to an implant is facilitated, and the material has a very good clinical application value. And the preparation process is simple, the cost is low, and the market popularization is facilitated.

Description

Titanium-based functional material with pore diameter gradient structure, preparation method and application

Technical Field

The invention belongs to the technical field of preparation of biomedical materials, and particularly relates to a titanium-based functional material with a pore diameter gradient structure, a preparation method and application.

Background

Titanium and its alloy are very attractive biomedical metal materials because of their excellent corrosion resistance, mechanical properties and processability, and their lower price than noble metal medical products, and their good biocompatibility compared with common metal materials. However, most medical titanium alloys are bio-inert materials, are not easy to induce the growth of surrounding tissue cells, and have elastic modulus much higher than that of human bones (10-30GPa), which can cause the mismatch between the implant material and the surrounding bones, generate stress shielding effect, cause the implant to loosen or break, and cause the graft failure. Therefore, in order to obtain titanium and titanium alloy having more excellent performance, it is common to modify the surface of titanium and titanium alloy material so that the bonding portion between the titanium alloy and the living body has more excellent performance, while keeping the matrix of the titanium and titanium alloy material unchanged.

The 3D printing technology, which is an additive manufacturing technology rapidly emerging in recent years, mainly includes a selective laser sintering technology and a selective laser melting technology. The outstanding advantages are that: the method has the advantages of short development period of parts, no need of a die and a complex post-treatment process, capability of directly manufacturing a near-terminal or even a terminal part, and high forming precision. The titanium material with the microporous structure prepared by the technology is beneficial to the growth of bone tissues and is widely concerned due to the increase of the cell contact area.

However, the microstructure of the titanium matrix prepared by the 3D printing technology is not uniform, and even has obvious defects so as to seriously affect the mechanical property of the titanium matrix. Therefore, there is a need to develop a new process to solve the above problems and prepare a titanium-based functional material with a porous structure for clinical application.

Disclosure of Invention

In view of the above disadvantages and drawbacks of the prior art, an object of the present invention is to provide a titanium-based functional material with a pore size gradient structure, a preparation method and an application thereof, so as to solve the problems of high elastic modulus and poor plasticity of the titanium-based functional material prepared by the prior art.

In order to achieve the purpose, the technical scheme is as follows:

a preparation method of a titanium-based functional material with a pore diameter gradient structure comprises the steps of preparing a titanium-based plate by a 3D printing method; digging a cavity groove on the titanium-based plate, and filling aluminum powder into the cavity groove to obtain a plate to be processed; stirring and rubbing the plate to be processed, and then carrying out acid pickling treatment to obtain the product; the depth of the cavity groove is 1/5-1/2 of the thickness of the titanium-based plate.

Optionally, the 3D printing method is selective laser melting; the titanium-based plate is a pure titanium matrix plate or a titanium alloy matrix plate; the thickness of the pure titanium matrix plate or the titanium alloy matrix plate is 3-5 mm; the cavity groove is a circular cavity groove, the depth of the cavity groove is 0.5-3 mm, the diameter of the cavity groove is 0.5-2 mm, and the space between the cavity grooves is 1-5 mm.

Optionally, the thickness of the powder layer in the selective laser melting process is 30-60 μm, the laser power is 300-500W, the scanning speed is 800-2000 m/s, the scanning distance is 0.08-0.15 mm, and the used gas is nitrogen, argon or helium.

Optionally, the raw material for preparing the titanium-based plate is pure titanium powder or titanium alloy powder, the pure titanium powder or titanium alloy powder is spherical powder, and the particle size is 5-60 mu m; the particle size distribution range of the aluminum powder is 1-5 mu m, and the purity is more than or equal to 99.9%.

Optionally, the rotation speed of the stirring head in the stirring and friction processing process is 200-1200 rpm, the advancing speed is 20-100 mm/min, and the reduction is 0.1-0.5 mm.

Optionally, the acid washing is performed by using HCl solution or H₂SO₄Solutions, HCl solutions or H₂SO₄The concentration of the solution is 0.5-10% mol/L, and the acid washing time is 10-300 s.

A preparation method of a titanium-based functional material with a pore diameter gradient structure specifically comprises the following steps:

the method comprises the following steps: placing pure titanium powder or titanium alloy powder into a powder box of selective laser melting equipment, vacuumizing the selective laser melting equipment, filling inert gas, and then melting, sintering and forming by using a high-energy laser beam to obtain a pure titanium substrate plate or a titanium alloy substrate plate, wherein the thickness of the pure titanium substrate plate or the titanium alloy substrate plate is 5-8 mm;

step two: digging circular cavity grooves on the surface of a pure titanium matrix plate or a titanium alloy matrix plate, wherein the depth of each cavity groove is 0.5-3 mm, the diameter of each cavity groove is 0.5-2 mm, and the space between the cavity grooves is 1-5 mm;

step three: aluminum powder is filled in the cavity groove, and the base plate added with the aluminum powder is subjected to stirring friction processing, wherein the rotating speed of the stirring head is 1180r/min, the advancing speed is 23.5mm/min, the pressing amount is 0.5mm, and the length of the stirring needle is 1.5 mm;

step four: acid cleaning treatment is carried out, namely the plate processed in the third step is soaked in HCl solution or H₂SO₄Solutions, HCl solutions or H₂SO₄The concentration of the solution is 0.5-10% mol/L, and the acid washing time is 10-300 s.

Optionally, the thickness of the powder spreading layer in the selective laser melting process is 30-60 μm, the laser power is 300-500W, the scanning speed is 800-2000 m/s, the scanning distance is 0.08-0.15 mm, and the inert gas is nitrogen, argon or helium.

The invention discloses a titanium-based functional material with a pore diameter gradient structure, which is prepared by the preparation method of the titanium-based functional material with the pore diameter gradient structure.

The titanium-based functional material with the pore diameter gradient structure is applied to preparing bone materials.

Compared with the prior art, the invention has the following technical effects: the titanium-based functional material with the pore diameter gradient structure prepared by the invention has a porous structure with different pore diameters on the surface and the matrix, and the whole material presents a rough porous appearance, so that the contact area of cells is enlarged, the growth requirements of different cells can be met, the growth of bone tissues to an implant is facilitated, and the titanium-based functional material has very good academic value and clinical application value.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is a process flow diagram of the titanium-based functional material with a pore size gradient structure and the preparation method thereof according to the present invention;

FIG. 2 is a schematic structural diagram of a titanium-based functional material having a pore size gradient structure according to the present invention;

FIG. 3 is a microstructure of a titanium substrate in example 1 of the present invention;

FIG. 4 is a microstructure of the surface of the titanium-based functional material prepared in example 1 of the present invention;

FIG. 5 is a microstructure of the surface of titanium-based functional material prepared in example 2 of the present invention.

Detailed Description

The invention is described in further detail below with reference to the figures and specific examples. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

Selective laser melting is a technique for melting metal powder by laser according to a specified path to finally form a metal solid entity, and can prepare a material with a micron-scale structure, but has the defects of high porosity, poor plasticity and toughness, uneven structure and the like. The friction stir processing is a large plastic deformation technology developed based on friction stir welding, and the technology can refine, homogenize and densify the structure of the processed material. The titanium matrix printed by 3D printing is processed by the technology, so that the defects and tissue nonuniformity of the material can be improved, and the elastic modulus of the material can be reduced. By combining the advantages of the technologies, the invention successfully prepares the titanium-based functional material with good plasticity and toughness and a pore-size gradient structure, and enriches the preparation method of the biomedical titanium-based composite material.

The invention provides a titanium-based functional material with a pore diameter gradient structure and a preparation method thereof, wherein the preparation method comprises the following steps: the method comprises the steps of firstly preparing a pure titanium or titanium alloy matrix plate by utilizing a selective laser melting technology, then punching or grooving the plate, filling pure aluminum powder in the holes or the grooves, then processing by adopting a stirring friction method, and finally removing aluminum particle clusters by acid washing to form a porous structure, thereby obtaining the porous titanium-based functional material with a pore diameter gradient structure.

With reference to fig. 2, the titanium-based functional material with a pore size gradient structure prepared by the invention has a fine porous layer on the surface layer, a crossed porous structure and a loose porous layer on the inner layer. The surface layer and the matrix have different pore diameter structures, are beneficial to the growth and fusion of bone tissues and have better plasticity and toughness.

The invention utilizes the stirring friction processing technology, can promote the refinement of alloy grains, reduce the porosity of the material and improve the comprehensive performance of the material. The material is a rough porous structure with pore diameter gradient, enlarges the contact area of cells, can meet the growth requirements of different cells, is beneficial to the growth of bone tissues to an implant, and has very good clinical application value. The preparation process is simple, the cost is low, and the market popularization is facilitated.

Specifically, the scheme of the invention is as follows:

a titanium-based functional material with a pore diameter gradient structure is prepared by taking pure titanium or titanium alloy prepared by a 3D printing technology as a matrix, then punching or grooving on the matrix, filling pure aluminum powder in holes or grooves, then processing by adopting a stirring friction method, and finally removing aluminum particle clusters by acid washing or alkali washing to form a porous rough structure, thereby obtaining the titanium-based functional material with the pore diameter gradient structure.

The pure titanium or titanium alloy powder is spherical powder with the particle size of 5-50 mu m;

furthermore, the thickness of a powder layer in the selective laser melting process is 30-60 mu m, the laser power is 300-500W, the scanning speed is 800-2000 m/s, the scanning distance is 0.08-0.15 mm, and the used gas is nitrogen, argon or helium.

Furthermore, the rotation speed of the stirring head in the stirring and friction processing process is 200-1200 rpm, the advancing speed is 20-100 mm/min, and the reduction is 0.1-0.5 mm.

Furthermore, the particle size distribution range of the pure aluminum powder is 1-5 mu m, and the purity is more than or equal to 99%.

Further, the acid solution for acid washing can be HCl or H₂SO₄The acid concentration is 0.5-10% mol/L, and the acid washing time is 10-300 s.

The following detailed description is made in conjunction with the flow chart of the preparation process of fig. 1, and specifically includes the following steps:

the method comprises the following steps: placing pure titanium or titanium alloy powder into a powder box of selective laser melting equipment, vacuumizing the selective laser melting equipment, filling argon gas, and then performing melting-sintering-forming by using a high-energy laser beam to obtain a pure titanium or titanium alloy substrate with the thickness of about 3-5 mm.

Step two: and (3) punching holes on the surface of the pure titanium or titanium alloy substrate, wherein the hole depth is 0.5-3 mm, the hole diameter is 0.5-2 mm, and the hole spacing is 1-5 mm.

Step three: and filling pure aluminum powder in the holes, and performing friction stir processing on the base plate after the powder is added, wherein the rotation speed of a stirring head is 1180r/min, the advancing speed is 23.5mm/min, the shaft shoulder reduction is 0.5mm, and the length of a stirring needle is 2.5-4.5 mm.

Step four: acid cleaning the titanium-based composite material, namely soaking the titanium-based composite material containing the aluminum powder in HCl or H₂SO₄The acid concentration is 0.5-10% mol/L, and the acid washing time is 10-300 s.

Step five: and ultrasonically cleaning the material in deionized water to obtain the titanium-based functional material with the pore diameter gradient structure.

Each of the raw materials in the present invention is commercially available.

Example 1:

a method for preparing a titanium-based functional material with a pore size gradient structure, comprising the following steps:

the method comprises the following steps: placing pure titanium powder with the particle size distribution range of 5-50 mu m into a powder box of selective laser melting equipment, wherein the used gas is argon, the laser power is 400W, the powder laying thickness is 0.04mm, the laser scanning interval is 0.09mm, the laser scanning speed is 1700mm/s, and the thickness of the prepared pure titanium substrate is 5 mm.

Step two: and (3) punching holes on the surface of the pure titanium substrate, wherein the depth of each hole is 1.5mm, the aperture is 2mm, and the hole distance is 2 mm.

Step three: pure aluminum powder is filled in the holes, and the base plate added with the powder is subjected to friction stir processing, wherein the rotation speed of a stirring head is 1180r/min, the advancing speed is 23.5mm/min, the shaft shoulder reduction is 0.5mm, and the length of a stirring needle is 1.5 mm.

Step four: the titanium-based composite material containing the aluminum powder is subjected to acid pickling treatment, namely the titanium-based composite material containing the aluminum powder is soaked in HCl, the acid concentration is 3.5% mol/L, and the acid pickling time is 120 s.

Step five: and ultrasonically cleaning the material in deionized water to obtain the titanium-based functional material with the pore diameter gradient structure, wherein the porous layer on the surface layer has a crossed porous structure.

The example successfully prepares a titanium-based functional material with a thickness of 5mm and a pore diameter gradient structure, wherein the surface layer is a pore fine uniform structure layer (the pore diameter is 9-13 mu m) with the thickness of 2mm, and the matrix is a loose and porous pure titanium block (the pore diameter is 200-300 mu m). As shown in FIG. 3, the titanium matrix prepared in the first step has a microscopic morphology, and it can be seen that the titanium matrix has high and large porosity and non-uniform tissue; the titanium-based functional material prepared in the figure 4 has a porous structure with different pore diameters from the substrate, and the pore diameter of the surface is smaller than that of the substrate. As shown in Table 1, the tensile strength of this material was 543MPa, the yield strength was 319MPa, the elongation was 22.1%, and the elastic modulus was 21 GPa. Compared with the titanium-based functional gradient material with porous surface prepared by FSP, the titanium-based functional material with the pore diameter gradient structure obtained by the method has higher elongation and lower Young modulus, is closer to the natural bone of a human body, and has relatively excellent comprehensive performance when being used as a bone repair material.

A porous titanium-based functionally gradient material prepared by FSP, a porous titanium-based functionally gradient material and a preparation method thereof are CN201910826550.1[ P ].2019-12-13.

Example 2:

the method comprises the following steps: placing TC4 powder with the particle size distribution range of 20-60 mu m into a powder box of selective laser melting equipment, wherein the used gas is argon, the laser power is 400W, the powder laying thickness is 004 mm, the laser scanning interval is 0.09mm, the laser scanning speed is 1700mm/s, and the thickness of the prepared TC4 substrate is 5 mm.

Step two: the TC4 matrix surface is punched, the hole depth is 1.5mm, the hole diameter is 1.5mm, and the hole spacing is 1.5 mm.

The example successfully prepares the titanium-based functional material with the thickness of 5mm and a pore diameter gradient structure, wherein the surface layer is a pore fine uniform structure layer (3-6 mu m) with the thickness of 2mm, and the matrix is a loose and porous TC4 titanium alloy block (200-300 mu m). The titanium-based functional material prepared in figure 5 has a porous structure with different pore diameters from the surface of the substrate. As shown in Table 1, the tensile strength of this material was 616MPa, the yield strength was 455MPa, the elongation was 12.1%, and the elastic modulus was 20 GPa. Compared with the porous Ti-Mo alloy prepared by 3D printing, the titanium-based functional material with the pore diameter gradient structure prepared by the invention has higher yield strength, lower elastic modulus and better comprehensive performance, and is more suitable for being used as a bone repair material.

Ti-Mo alloys, see Xie F X, He X B. Cao S L.et a1.structural characteristics and chemical instrumentation of a laser-located pole Ti-l0 Mo alloy [ J ]. corporation Science,2013,67:217.

Example 3:

the method comprises the following steps: placing pure titanium powder with the particle size distribution range of 20-60 mu m into a powder box of selective laser melting equipment, wherein the used gas is argon, the laser power is 400W, the powder laying thickness is 004 mm, the laser scanning interval is 0.09mm, the laser scanning speed is 1700mm/s, and the thickness of the prepared pure titanium substrate is 5 mm.

Step two: the surface of the pure titanium substrate is punched, the hole depth is 1mm, the hole diameter is 1.5mm, and the hole distance is 2 mm.

Step three: pure aluminum powder is filled in the holes, and the base plate added with the powder is subjected to friction stir processing, wherein the rotation speed of a stirring head is 1180r/min, the advancing speed is 23.5mm/min, the shaft shoulder reduction is 0.5mm, and the length of a stirring needle is 1 mm.

The example successfully prepares a titanium-based functional material with a 5mm thickness and a pore size gradient structure, wherein the surface layer is a 1.5mm thick pore fine uniform structure layer (3-6 mu m), and the matrix is a loose and porous pure titanium block (200-300 mu m). As shown in Table 1, the tensile strength of this material was 521MPa, the yield strength was 323MPa, the elongation was 15.6%, and the elastic modulus was 45 GPa. The titanium-based functional material with the pore diameter gradient structure prepared by the invention has better comprehensive performance and is suitable for being used as a bone repair material.

Example 4:

Step two: the TC4 matrix surface is punched, the hole depth is 0.5mm, the hole diameter is 1.5mm, and the hole spacing is 1.5 mm.

The example successfully prepares the titanium-based functional material with the thickness of 5mm and a pore diameter gradient structure, wherein the surface layer is a 1.5mm thick pore fine uniform structure layer (3-6 mu m), and the matrix is a loose and porous TC4 titanium alloy block (200-300 mu m). As shown in Table 1, the tensile strength of this material was 608MPa, the yield strength was 462MPa, the elongation was 7.4%, and the elastic modulus was 48 GPa. The titanium-based functional material with the pore diameter gradient structure prepared by the invention has better comprehensive performance and is suitable for being used as a bone repair material.

Table 1 shows the tensile test results of titanium-based functional materials having a pore size gradient structure prepared in examples 1 to 4 of the present invention.

Test items	Example 1	Example 2	Example 3	Example 4
					Tensile strength/MPa	543	616	521	608
Yield strength/MPa	319	455	323	462
					Elongation/percent	22.1	12.1	15.6	7.4
Modulus of elasticity/GPa	21	20	45	48

The above-mentioned embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the scope of the invention, and therefore all equivalent variations made by the following claims should be included in the scope of the invention.

Claims

1. A preparation method of a titanium-based functional material with a pore diameter gradient structure is characterized in that a titanium-based plate is prepared by a 3D printing method;

digging a cavity groove on the titanium-based plate, and filling aluminum powder into the cavity groove to obtain a plate to be processed;

stirring and rubbing the plate to be processed, and then carrying out acid pickling treatment to obtain the product;

the depth of the cavity groove is 1/5-1/2 of the thickness of the titanium-based plate.

2. The method for preparing titanium-based functional material with pore size gradient structure as claimed in claim 1, wherein the 3D printing method is selective laser melting; the titanium-based plate is a pure titanium matrix plate or a titanium alloy matrix plate;

the thickness of the pure titanium matrix plate or the titanium alloy matrix plate is 3-5 mm;

the cavity groove is a circular cavity groove, the depth of the cavity groove is 0.5-3 mm, the diameter of the cavity groove is 0.5-2 mm, and the space between the cavity grooves is 1-5 mm.

3. The method for preparing the titanium-based functional material with the pore diameter gradient structure as claimed in claim 2, wherein the powder spreading layer in the selective laser melting process is 30-60 μm thick, the laser power is 300-500W, the scanning speed is 800-2000 m/s, the scanning distance is 0.08-0.15 mm, and the used gas is nitrogen, argon or helium.

4. The method for preparing the titanium-based functional material with the pore size gradient structure as claimed in claim 1, 2 or 3, wherein the raw material for preparing the titanium-based plate is pure titanium powder or titanium alloy powder, the pure titanium powder or titanium alloy powder is spherical powder, and the particle size is 5-60 μm;

the particle size distribution range of the aluminum powder is 1-5 mu m, and the purity is more than or equal to 99.9%.

5. The method for preparing the titanium-based functional material with the pore diameter gradient structure as claimed in claim 1, 2 or 3, wherein the rotational speed of the stirring head during the friction stir processing is 200-1200 rpm, the forward speed is 20-100 mm/min, and the reduction is 0.1-0.5 mm.

6. The method for preparing titanium-based functional material with pore size gradient structure as claimed in claim 1, 2 or 3, wherein HCl solution or H is selected for pickling₂SO₄Solutions, HCl solutions or H₂SO₄The concentration of the solution is 0.5-10% mol/L, and the acid washing time is 10-300 s.

7. A preparation method of a titanium-based functional material with a pore diameter gradient structure is characterized by comprising the following steps:

8. The method for preparing the titanium-based functional material with the pore diameter gradient structure as claimed in claim 7, wherein the powder spreading layer in the selective laser melting process is 30-60 μm thick, the laser power is 300-500W, the scanning speed is 800-2000 m/s, the scanning distance is 0.08-0.15 mm, and the inert gas is nitrogen, argon or helium.

9. A titanium-based functional material with a pore size gradient structure, which is prepared by the preparation method of the titanium-based functional material with the pore size gradient structure as claimed in any one of claims 1 to 8.

10. Use of the titanium-based functional material with a pore size gradient structure according to claim 9 for the preparation of bone material.